YZ125 Modifications PackagesHP is a world leader in yz125 race engines

YZ125 Mod Stage 1 | $500Our starter package for the yz125 makes around 37 hp, is extremely reliable, and will do it with a stock pipe, stock reeds-Cylinder porting stage 1-Head Mods-Set up notes on timing and jetting

YZ125 Mod Stage 2 | $1350This combo is truly incredible for a 125cc engine at an even better price, pushes the yz to the 39hp mark with great mid range.-Cylinder porting stage 2-Head mods-Reed cage-Pipe and silencer combo-Set up notes on timing and jetting

YZ125 134 Cylinder Conversion | $ 800Our 134 combo drops on stock cases and makes stupid power. If you are racing thr 125 in schoolby 2, local racing, or just want a killer big bore without case mods, this combo is insane.-Cylinder boring-144 porting, tailored to each customer-Powervalve machining-144 head machining specific to fuel and customer-Replating-Piston and gasket kit

YZ125 144 Cylinder Conversion | $900Our yz144 has pushed the amount of power thought possible out of a yz125. We have hit 45 hp on some builds! Requires case clearance.-Cylinder boring-144 porting, tailored to each customer-Powervalve machining-144 head machining specific to fuel and customer-Replating-Piston and gasket kit

YZ250 Modifications Packages

Yz250 Mod Stage 1 | $400More fun than you can imagine, this combo outruns those pesky KTM's when on the pipe, and outruns the competitions yz 300's.-Porting Stage 1-Head Mods-Set up notes for timing and jetting

YZ250 Stage 2 | $1100Would have put the factory bikes to shame-Porting and Epoxy Work Stage 2-Head mods-Carb Mod, jetting​-Custom Piston kit included-Set up notes on timing**we offer an HPI ignition box for this as well